The invention provides methods for obtaining cell populations enriched in microglial cells. The invention finds application in the fields of medical, cell biology, and pharmacology (e.g., drug development).
Microglial cells are small neuroglial cells of monocyte lineage residing in the central nervous system. These cells are quiescent under normal physiological conditions, but become activated in areas of neural damage or inflammation, and in various neurological disorders, including stroke, Alzheimer""s disease, Parkinson""s disease, and multiple sclerosis (see, e.g., Gonzalez-Scarano et al., 1999, Ann. Rev. Neurosci. 22:219-40; Kreutzberg, 1996, Trends Neurosci. 19:312-18). The study and use of isolated microglial cells and purified microglial cell populations (including, for example, characterizing the interaction of these cells with the in vitro or in vivo environment and with drugs and drug candidates) will provide information useful in treating neurological disorders. Improved methods for preparing highly purified populations of microglial cells are thus useful in understanding and treating the pathological processes of disorders of the central nervous system.
In one aspect, the invention provides a method for obtaining a cell population enriched in microglial cells. In an embodiment, the method involves contacting a composition comprising microglial cells (e.g., a dissociated tissue, such as dissociated brain) with immunoglobulin, wherein the immunoglobulin is immobilized on a matrix prior to or after said contacting allowing the microglial cells to bind the immobilized immunoglobulin; and removing non-adherent cells. In some embodiments, the resulting microglial cells are cultured on the matrix to which the immunoglobulin is immobilized.
In some embodiments of the invention the immunoglobulin comprises immunoglobulin G (IgG). Often the microglial cells to be purified and the immunoglobulin are from the same species (e.g., a mammal such as rat or human). In some embodiments, the microglial cells are be from brain (e.g., from human, rat, or mouse brain) and may be from a normal animal or from a patient or animal with a neurological disorder.
In some embodiments, the matrix is a plastic, such as polystyrene. The matrix may be in a variety of forms, e.g., in the form of a dish, coverslip, or bead.
In another aspect, the invention provides a composition comprising a microglial cells produced according to the method. Often, at least about 95% of the cells in the composition are microglial cells.